Gas turbine engine vane end devices

ABSTRACT

A turbomachinery component of a gas turbine engine is disclosed having a number of techniques of reducing the effects of a gap flow between an airfoil member of the gas turbine engine and a wall of the gas turbine engine. The airfoil member can be a variable and in one form is a variable turbine vane. In one embodiment a brush seal is included between the vane and the wall. In another form a wear surface is disposed between the vane and the wall. In yet another form a moveable member capable of being actuated to change position can be disposed between the vane and the wall to alter the size of a gap between the two.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 61/769,535, filed 26 Feb. 2013, the disclosure ofwhich is now expressly incorporated herein by reference.

GOVERNMENT RIGHTS

The present application was made with the United States governmentsupport under Contract No. FA8650-07-6-2803. The United Statesgovernment has certain rights in the present application.

TECHNICAL FIELD

The present invention generally relates to moveable flow structures ingas turbine engines, and more particularly, but not exclusively, to gapflows in gas turbine engines.

BACKGROUND

Mitigating and/or reducing a flow of fluid between an end of a movableairfoil member in a gas turbine engine and an adjacent wall remains anarea of interest. Some existing systems have various shortcomingsrelative to certain applications. Accordingly, there remains a need forfurther contributions in this area of technology.

SUMMARY

One embodiment of the present invention is a unique gas turbine enginemoveable airfoil member. Other embodiments include apparatuses, systems,devices, hardware, methods, and combinations for discouraging flowbetween an end of a variable vane and a wall of a gas turbine engine.Further embodiments, forms, features, aspects, benefits, and advantagesof the present application shall become apparent from the descriptionand figures provided herewith.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts an embodiment of a gas turbine engine;

FIG. 2A depicts an embodiment of a brush seal;

FIG. 2B depicts an embodiment of a brush seal;

FIG. 3 depicts an embodiment of a wear surface;

FIG. 4A depicts an embodiment of a moveable member; and

FIG. 4B depicts an embodiment of a moveable member.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. Any alterations and further modificationsin the described embodiments, and any further applications of theprinciples of the invention as described herein are contemplated aswould normally occur to one skilled in the art to which the inventionrelates.

With reference to FIG. 1, one embodiment of a gas turbine engine 50 isdepicted which includes turbomachinery components such as a compressor52 and turbine 54 which operate to produce power. In operation the gasturbine engine 50 produces power by receiving a working fluid into thecompressor 52 and compressing, mixing the working fluid with a fuel andcombusting the mixture in a combustor 56. The working fluid and/orproducts of combustion can be expanded in the turbine 54 to produce workbefore being exhausted downstream of the turbine 54. The turbomachineryof the engine 50 generally includes a rotating bladed rotor, or likedevice, capable of turning at relatively high speed as a working fluidis passed through the turbomachinery. The gas turbine engine componentscan also include one or more row of vanes that can be used to turn afluid flow either upstream or downstream of the bladed rotor. Forexample, the turbine 54 can include a row of vanes to assist in turningthe flow upstream of a row of rotating blades. The vanes can beselectively turned, or pivoted, to change the amount of flow turningupstream of the blades. The gas turbine engine can have any number ofblade rows and vane rows depending on the application. Though the vanescan be located immediately upstream of a row of rotatable blades it willbe appreciated that the vanes can be placed in other locations, whetheror not immediately adjacent upstream of the blades. To set forth justone non-limiting example, the vanes can be an inlet guide vane or anoutlet guide vane. The vanes can also be positioned downstream of therotatable row of blades. Various configurations are contemplated herein.

Though the gas turbine engine 50 is depicted in the illustratedembodiment as a single spool engine, in other embodiments the gasturbine engine can include any number of spools. The gas turbine engine50 can take on a variety of forms including a turbojet, turbofan,turboshaft, and turboprop engine. In some forms the gas turbine engine50 can be a variable cycle and/or adaptive cycle engine. In onenon-limiting form the gas turbine engine 50 can be used to provide powerto an aircraft whether that power is in the form of propulsive thrust,mechanical power, electrical power, or otherwise.

As used herein, the term “aircraft” includes, but is not limited to,helicopters, airplanes, unmanned space vehicles, fixed wing vehicles,variable wing vehicles, rotary wing vehicles, unmanned combat aerialvehicles, tailless aircraft, hover crafts, and other airborne and/orextraterrestrial (spacecraft) vehicles. Further, the present inventionsare contemplated for utilization in other applications that may not becoupled with an aircraft such as, for example, industrial applications,power generation, pumping sets, naval propulsion, weapon systems,security systems, perimeter defense/security systems, and the like knownto one of ordinary skill in the art.

Turning to FIGS. 2 a and 2 b, one embodiment of a turbomachinerycomponent in the form of a vane 58 is depicted having a seal disposed atone end. The vane 58 includes a spindle 60 that can be coupled with anactuation mechanism and used to change a position of the vane 58. Forexample, the spindle 60 can be coupled directly to an actuator oralternatively can be coupled to an actuator via a common sync ringshared by a number of other vanes 58. The spindle 60 or other suitablestructure can be used to support the vane 58 within the flow path of thegas turbine engine such that the vane 58 is cantilevered. In some formsthe vane 58 can be supported on both ends of its span. In theillustrated embodiment the vane 58 is shown supported on one end but itwill be appreciated that different embodiments may include othervariations. The vane 58 can be one of a plurality of variable vanes 58in a row, all of which can be actuated to change a position to redirecta flow of working fluid through the turbomachinery component. The vane58 is generally disposed between walls that define a flow path of thegas turbine engine. As shown in the illustrated embodiment the vane 58is positioned adjacent a wall 62. Though a corresponding wall is notdepicted in FIGS. 2 a and 2B it will be appreciated that the other wallis in proximity to the opposing side of the vane 58.

The wall 62 of the turbomachinery component is generally non-planar inmany embodiments and thus certain embodiments of the vane 58, whenpivoted to various positions, creates a gap between the wall 62 and aportion of the vane sometimes referred to as an overhang 64 of the vane58. The overhang 64 can be designed to permit a movement of the vane 58such that little to no interaction occurs between the wall 62 and thevane 58. In some forms the vane 58 can be rotated to positions whichcreate contact with the wall 62 of the turbomachinery component. To setforth just one non-limiting example, the overhang 64 may contact thewall of the turbomachinery component at either or both the maximumposition and the minimum position thus creating a gap over the portionof vane travel between one or both of the maximum position and minimumposition. In any event, the gap between the vane 58 and the wall 62 canbe created at some positions of the vane 58 when pivoted and maydisappear at other positions when the vane 58 contacts the wall 62. Thesize of the gap can be the same size along the length of the vane 58,but in some forms the size of the gap can vary depending on the chordlocation. For example, near a trailing edge of the vane 58 the gap canbe larger than at a location nearer a leading edge of the vane 58.Though the illustrated embodiment is depicted having just one wall 62,it will be appreciated that a gap can be formed between the vane 58 anda wall opposing the wall 62. Such a gap can have the samecharacteristics as the gap discussed above with respect to the vane 58and wall 62, but some embodiments may include variations between thegaps.

A seal 66 can located between the vane 58 and the wall 62 to discouragea flow of working fluid from one side of the vane to the other, forexample from a relatively high pressure side to a relatively lowpressure size. In the illustrated embodiment the seal extends from thevane 58 and is in the form of a brush seal having a number of bristles68 located along a portion of the chord of the vane 58. The bristles 68can contact the wall 62 at all positions of the vane 58, but in someembodiments one or more portions of the bristles 68 may not contact thewall 62 at all positions. The brush seal 66 can include one or morebristles 68 that are flexible such that when contact is made with thewall 62 the bristles 68 will flex. The flexible nature of the bristles68 can permit some degree of variation in the gap between the end of thevane 58 and the wall 62 as the vane 58 is rotated to new positions. Forexample the bristles 68 can flex greater amounts at a position where thegap is small and flex relatively little where the gap is large. Thebristles 68 can be made of a variety of materials using a variety ofprocesses. In one non-limiting form the bristles 68 are made of ceramicfiber.

In some embodiments the seal 66 can extend along the entirety of thechord of the vane 58. For example, the brush seal 66 can extend betweena leading edge and a trailing edge and be located on both sides of thespindle 60. In some forms the brush seal 66 can be grouped into separateportions. Other variations are contemplated. A brush seal 66 can also belocated on the opposite end of the vane 58, though the illustratedembodiment depicts a brush seal on just one end of the vane 58. In thoseembodiments having brush seals 66 disposed on both ends of the vane 58,the seals 66 can be arranged similarly but in some forms the seals 66can have different configurations.

The height of the bristles 68 in the brush seal 66 can vary. In onenon-limiting form the reach of the bristles 68 between the vane 58 andthe wall 62 can vary with chord location. For example, the bristles 68can be relatively short near the leading edge and relatively long nearthe trailing edge. Additionally and/or alternatively, the bristles 68can vary individually regardless of chord location such as variations inbristles that are located near the same chord location.

The brush seal 66 can include groupings of bristles 68. For example, thebrush seal 66 can include one grouping disposed toward the suction sideand another grouping disposed toward the pressure side of the vane.Additional or fewer groupings can be used in other embodiments. Othervariations are also contemplated herein.

FIGS. 2 a and 2 b depict just one embodiment of the bristles 68 and amechanism 70 to couple the bristles 68 to the vane 58. The mechanism 70includes a clamp 72 and a base member 74 around which the bristles 68are coupled. The clamp 72 is used in the illustrated embodiment toretain the bristles 68 to the base member 74. One or more clamps 72 canbe used though the illustrated embodiment depicts just one clamp 72. Theclamp 72 can be metallic and in some applications takes the form of acrimp. In some embodiments the mechanism 70 can include bristles 68 thatare bonded or affixed to the base member 74 using techniques other thanthe claim 72. Other mechanisms are contemplated herein. To set forthjust one non-limiting example, the bristles 68 can be individuallyattached to a base such that they are not wound around a member, such asthe base member 74, but rather extend from an attachment.

The base member 74 in the illustrated embodiment includes a circularcross section but other cross sections are contemplated. The member 74can extend along the chord of the vane 58 a variety of lengths. In someforms the member 74 can be formed integral with the vane 58 while inother forms the member 74 can be coupled to the vane 58 using a varietyof techniques. In some forms the base member 74 need not be straight butcan rather take on other shapes. Any number of base members 74 can beused.

The base member 74 around which the bristles 68 are coupled can beoriented parallel with an end of the vane 58. In some embodiments thebase member 74 can be oriented at an angle whether that angle ismeasured relative to the vane 58 or relative to the wall 62 when thevane 58 is positioned within the flow path of the gas turbine engine 50.To set forth just one non-limiting example, the base member 74 can beoriented such that a portion located toward the leading edge of the vane58 is positioned further away from an end of the vane 58 than a portionof the base member 74 located toward the trailing edge.

Turning now to FIG. 3, another embodiment of the vane 58 is disclosedwhich includes a wear surface 76 disposed between the vane 58 and thewall 62. In one form the wear surface 76 is configured to be abradedwhen relative movement causes the vane 58 and the wall 62 to contacteach other. The wear surface 76 is shown disposed on the tips ofsquealer members 78 of the vane 58, but in some forms of the vane 58 thewear surface 76 can be located at the end of the vane 58 whether or notthe vane includes the squealer members 78. Both ends of the vane 58 caninclude the wear surface 76, whether or not both ends also include thesquealer members 78. The wear surface can be a coating that is appliedto the vane 58 using any number of processes. The wear surface 76 can beconfigured to provide for variable wear rates and in some forms is madeof a different material than the vane 58. In some forms the wear surface76 can therefore have different material properties, such as densityamong potential others.

The wear surface 76 can be used to allow for geometric variations in thecontact points between the vane 58 and the coating. For example, thewear surface 76 may wear more heavily at a point between a leading edgeand a trailing edge of the vane 58. In some applications a side of thewear surface 76 disposed toward one of the pressure side and suctionside of the vane 58 may wear more than another side. For example, asquealer member 78 disposed on a pressure side of the vane 58 mayexperience greater wear of its wear surface 76 than the squealer member78 disposed toward the suction side of the vane 58. It is also possiblethat one edge of the squealer member 78 can provide for a greater wearthan another edge of the same squealer member. The wear surface 76 mayhave a variety of thicknesses which can change with its relativelocation in the vane 58. For example, the wear surface 76 may be thickernear the trailing edge than that near the leading edge of the vane 58.One squealer member 78 can also have a thicker wear surface 76 thananother squealer member 78.

The squealer members 78 can be integral to the vane 58, but in someforms the squealer members 78 can be coupled with the vane 58. Thoughtwo squealer members 78 are shown, in some embodiments the vane 58 caninclude fewer or greater numbers of squealer members 78. The squealermember 78 can have a variety of shapes and sizes. For example, in onenon-limiting example a squealer member 78 can continuously extend aroundthe vane 58 and have the shape of an airfoil. The squealer can also havea variety of shapes upon which the wear surface 76 is applied. In someforms the wear surface 76 is applied as a coating upon a shape of thetip of the squealer member 78 that is in the form of a relatively flatshelf. In some forms the material that constitutes the wear surface 76constitutes a majority of the squealer member 78. In other forms thematerial forming the wear surface is the entirety of the squealer member78.

In the illustrated form a cooling hole 80 is included the vane 58, butnot all embodiments need include the cooling hole 80. In one form thecooling hole is an effusion hole. The cooling hole 80 can be oriented atan angle, as depicted, or can be normal to a surface of the vane 58 andcan be capable of flowing a cooling flow at a variety of flow rates,pressures, and temperatures. Multiple cooling holes 80 can be includedin some forms of the vane 58.

FIGS. 4 a and 4 b disclose yet another embodiment of the vane 58 whichincludes a moveable member 82 that can be used to modulate and/or closethe size of the gap between the vane 58 and the wall 62. In theillustrated form the moveable member 82 includes a piston 84 receivedwithin the vane 58 and which includes a head 86 capable of being placedinto contact with the wall 62. Other forms of moveable members are alsocontemplated to modulate and/or close the size of the gap between thevane 58 and wall 62. In some embodiments the shape of the piston mayensure contact between the wall 62 and the vane 58 over the desiredrange of motion of the vane 58. For example, the shape of an end of thepiston can be curvilinear to accommodate interaction with the wall 62.The degree to which the piston shape is curved can be dependent on aparticular chord location. The piston can take on other shapes. Inoperation of the illustrated embodiment a relative pressure differencebetween an interior 88 of the vane 58 and an exterior of the vane 58,such as the flow path of the gas turbine engine 50, can be used tomanipulate a location of the moveable member 82. The relative pressuredifference can be modulated using suitable sensors and controls tochange the position of the piston. In some forms the pressure can bemodulated to selectively engage the piston with the wall 62. To setforth just one non-limiting example, the pressure can be modulated toensure contact of the piston with the wall 62 over a range of vanepositions.

Though the illustrated embodiment depicts a single moveable member 82disposed on one end of the vane 58, other embodiments can includemoveable members 82 at both ends of the vane 58. Alternatively and/oradditionally, more than one moveable member 82 can be disposed at anygiven end of the vane 58. In embodiments having moveable members 82 atboth ends of the vane 58, each of the moveable members 82 can beconfigured independent of the other. To set forth just a fewnon-limiting examples, the shape and size of the moveable members 82 canbe different. The moveable members 82 can be independently ordependently moveable relative to the other.

The piston head 86 is configured in the illustrated embodiment to extendto the sides of the vane 58. In some forms the piston head 86 may extendout of the interior 88 and not include a portion that extends to one ormore of the sides of the vane 58. The piston head 86 may also extend toone or more sides of the vane depending on its chord location. Forexample, in one non-limiting example the piston head 86 may extend tothe sides at a location near a leading edge of the vane 58 but may notextend to the sides of the vane 58 near the trailing edge of the vane58. A variety of configurations are contemplated herein.

The shape and size of the piston head 86 can be different depending onlocation in the vane 58. For example, the piston head 86 may have alarger thickness between sides of the vane 58 but relatively smallerheight as it extends from the vane at a location near the leading edgeof the vane 58, while also having a relatively smaller thickness butlarger height near the trailing edge of the vane 58.

A seal 90 is disposed between the piston 86 and the vane 58 and is usedto discourage a flow of working fluid between the interior 88 of thevane 58 and the flow path of the gas turbine engine. The working fluidcan take a variety of forms and in one non-limiting embodiment is aworking fluid from the compressor 52 of the gas turbine engine. The seal90 can take a variety of forms and can include one or more individualseals. In some applications the seal 90 can extend around the peripheryof the piston 84 while in other forms the seal 90 may extend around onlypart of the periphery of the piston 84. Such applications may includeadditional seals to extend the remainder, or partial remainder aroundthe piston 86. In other forms additional seals can be located at otherspan locations of the vane 58.

The seal 90 can be formed from a variety of materials using a number ofdifferent processed. To set forth just a few non-limiting examples ofmaterial type, the seal 90 can be made from ceramic or can be metallic.In one non-limiting example, the seal 90 can be a rope seal. The seal 90can be constructed such that it can expand to engage the piston 84. Insome forms the seal 90 can expand to form a relatively secure fit tosubstantially discourage working fluid from traversing the seal. Theseal 90 can expand upon heating and/or may expand as a result of beingcompressed during an assembly process of the vane 58.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiments have been shown and described and thatall changes and modifications that come within the spirit of theinventions are desired to be protected. It should be understood thatwhile the use of words such as preferable, preferably, preferred or morepreferred utilized in the description above indicate that the feature sodescribed may be more desirable, it nonetheless may not be necessary andembodiments lacking the same may be contemplated as within the scope ofthe invention, the scope being defined by the claims that follow. Inreading the claims, it is intended that when words such as “a,” “an,”“at least one,” or “at least one portion” are used there is no intentionto limit the claim to only one item unless specifically stated to thecontrary in the claim. When the language “at least a portion” and/or “aportion” is used the item can include a portion and/or the entire itemunless specifically stated to the contrary.

What is claimed is:
 1. An apparatus comprising: a moveable airfoilmember structured for use in a working fluid flow path of a gas turbineengine; and a brush seal disposed at an end of the moveable airfoilmember, the brush seal having a plurality of extensions projectingoutwardly and configured to discourage a flow of working fluid throughthe extensions as the working fluid traverses the working fluid flowpath.
 2. The apparatus of claim 1, which further includes the gasturbine engine, the engine including a plurality of the moveable airfoilmembers, wherein each of the plurality of moveable airfoil members is arotatable vane that includes a range of travel, and wherein theextensions contact the wall in the range of travel.
 3. The apparatus ofclaim 1, wherein the plurality of extensions each have a first end and asecond end both disposed toward a distal side of the plurality ofextensions, the first end and second end connected via a body that islooped around a central member.
 4. The apparatus of claim 3, whichfurther includes a crimp to couple the plurality of extensions to thecentral member, the central member extending along a chord of themoveable airfoil member, and wherein the moveable airfoil member is arotatable turbine vane.
 5. The apparatus of claim 1, wherein theplurality of extensions cover a portion of the chord between the leadingedge and trailing edge.
 6. The apparatus of claim 1, wherein theplurality of extensions include flexible extensions capable of flexingwhen placed in contact with a wall of the gas turbine engine, and whichfurther includes a gas turbine engine having a plurality of therotatable vanes.
 7. The apparatus of claim 6, wherein an amount offlexing is dependent upon a position of the vane, and wherein theplurality of extensions creates a plurality of tortuous flow pathsbetween an upstream side and a downstream side of the plurality ofextensions.
 8. An apparatus comprising: a rotatable airfoil member for agas turbine engine having an end structured to contact a wall of the gasturbine engine, the end having an abradable coating configured to wearaccording to a contact between the coating and the wall of the gasturbine engine.
 9. The apparatus of claim 8, wherein the rotatableairfoil member is disposed adjacent a rotatable blade and is configuredto turn a working fluid.
 10. The apparatus of claim 9, wherein the endincludes a squealer tip, and wherein the coating is applied to an endportion of the squealer tip.
 11. The apparatus of claim 10, wherein therotatable airfoil member is a turbine vane, wherein the vane includes acooling hole disposed between opposing squealer tips, and wherein one ofthe opposing squealer tips is disposed toward a relatively low pressureside of the vane and the other of the opposing squealer tips is disposedtoward a relatively high pressure side of the vane.
 12. The apparatus ofclaim 8, wherein the squealer tip coating is made of a first materialand the end of the vane is made of a second material, and which furtherincludes a gas turbine engine having the rotatable airfoil member. 13.The apparatus of claim 12, wherein the first material is different thanthe second material.
 14. The apparatus of claim 12, wherein a density ofthe first material is different than a density of the second material.15. An apparatus comprising: a rotatable airfoil member of a gas turbineengine having a surface that defines an internal opening and capable ofbeing positioned at a plurality of orientations, the rotatable airfoilmember operable to be disposed within a flow path of the gas turbineengine; a fluid obstruction received within the internal opening andconfigured to adjust toward and away from the internal opening to engagea wall of the gas turbine engine as the rotatable airfoil member ispositioned at the plurality of orientations; and a seal disposed betweenthe surface of the internal opening and the fluid obstruction, the sealstructured to discourage a flow of working fluid between the internalopening of the rotatable airfoil member and the flow path of the gasturbine engine.
 16. The apparatus of claim 15, wherein the fluidobstruction extends along a portion of a chord of the rotatable airfoilmember and which further includes a gas turbine engine having aplurality of the rotatable airfoil members.
 17. The apparatus of claim15, wherein the fluid obstruction includes a rounded head that isstructured to engage the wall, wherein the seal discourages passage ofair between a working flow path of the gas turbine engine and aninternal space of the rotatable airfoil member, and wherein therotatable airfoil member is a variable turbine vane.
 18. The apparatusof claim 15, wherein the fluid obstruction includes a first portionreceived within the internal opening and a second portion structured toengage the wall of the gas turbine engine.
 19. The apparatus of claim18, wherein the second portion extends beyond the internal opening to atleast one of a pressure side and a suction side of the gas turbineengine, wherein the seal is a rope seal, and wherein the rotatableairfoil member is a turbine vane.
 20. The apparatus of claim 15, whereinthe fluid obstruction is pneumatically actuated and wherein the internalopening receives a relatively pressurized fluid, and wherein the fluidobstruction includes a portion that extend beyond the surface of theinternal opening toward at least one of a relatively high pressure sideand a relatively low pressure side of the rotatable airfoil member.